What is chickenpox?
Chickenpox, or varicella, is a contagious disease caused by a virus. The technical name for this virus is varicella-zoster, a member of the herpes virus family. Chickenpox is considered by many experts to be a relatively harmless childhood disease. Symptoms include a fever, runny nose, sore throat, and an itchy skin rash which can appear anywhere on the body. The rash and disease usually disappear after one or two weeks. The disease confers permanent immunity; the child will not contract it again.

Is chickenpox dangerous?
Chickenpox can be itchy and uncomfortable for a few days. Serious problems are rare. In fact, before a chickenpox vaccine was introduced, doctors used to recommend exposing your child to the virus, and parents organized "chickenpox parties," because complication rates increase when the disease is contracted by teenagers or adults.(1) Every year, of the millions of people in the United States who contract this disease, about 50 die from related complications.(2) Many of these are in adults who did not have chickenpox as a child, or in previously unhealthy children -- youngsters with already weakened immune systems from other diseases, such as AIDS, leukemia, or cancer.(3-5)

How safe is the chickenpox vaccine?
The Vaccine Adverse Event Reporting System (VAERS), the federal organization established by Congress in 1986 to document adverse reactions to vaccines, received nearly 10,000 reports involving the chickenpox vaccine between the months of March 1995 and December 1999, a period of less than five years. The FDA and CDC studied 6,574 of these reports -- those filed between March 17, 1995 and July 25, 1998 -- and published their findings in the Journal of the American Medical Association.(19) Here is a summary of their findings:

Adverse reactions in recipients of the chickenpox vaccine occurred at a rate of 67.5 reports per 100,000 doses sold. Approximately four percent of reports described "serious" adverse reactions. By FDA definition, "serious" reactions refer to deaths, life-threatening events, hospitalizations, persistent or significant disabilities, and other incidents of medical importance. For example, the data analyzed in this report included numerous cases of neurological disorders, immune system damage, blood disorders, brain inflammation, seizures, and death (Figure 1).

These figures do not take into account the FDA's own admission that "potentially substantial under-reporting" made the figures "highly variable fractions of actual event numbers."(20) Nor do these figures take into account that "doses sold" (about 9.7 million through July 1998) is a CDC "projection" for which no reliable documentation can be found. Authors of the study based their figures on "oral" and private "unpublished data" from the CDC.(21,22) In some parts of the country vaccination rates are below 10 percent.(23,24) If the CDC inflated the actual number of doses sold, the true rate of adverse reactions following administration of the chickenpox vaccine is much higher.

The Vaccine Safety Manual
contains the most extensive information available
on the chickenpox (and shingles) vaccines.